Stylus-bar control for phonographs



R w. MORRISON.

STYLUS BAR CONTROL FOR PHONOGRAPHS.

APPLICATION FILED SEPT. 11, 1919.

1 ,357,338. Patented Nov. 2, 1920.

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UNITED STATES RALPH W. MORRISON, 01 OMAHA, NEBRASKA.

STYLUS-BAR CONTROL FOP PI-IGNOGRAPH rears-res.

Application filed September 11, 1919.

Z '0 all 'LU/LOi/L it may concern Be it known that 1, iirriirii it". iiionmsozv, a citizen of the United States, residing at Omaha, in the county of Douglas and State of Nebraska, have invented certain new and useful Improvements in Stylusliar Con trols for Phonographs, of which the following is a specification.

This invention relates to an eleotro-magnetic reproducer for phono raphs, and has for its object to provide means to normally maintain the stylus within the spiral groove during the rotation of the disk-record, this being of great advantage ince the case may be disposed inclinedly and accidental shocks or jars may effect a displacement of the stylus and cause it to move transversely from one groove to another; another object being to provide such a mounting for the stylusbar and cord that the sounds produced will be more clear and musical than ordinary, and to provide such a connection for the cord with the stylus-bar and diaphragm, that the cord will have uniform tension during the rocking movements of said bar.

In the accompanying drawing which illustrates one embodiment of the invention, Figure l is a" view in side elevation of a reproducer and its connections, parts being broken away and in section. i2 is a bottom plan view of the reproducer shown in Fig. 1. Fig. 3 is an enlarged detail relating to Fig. 1, Darts being in section. Fig. l is an enlarged detail relating to Fig. 3, showing the cord connection with the stylus-bar and diaphragm.

The invention is illustrated in connection with the tone-arm 5 and reproducer 6 of a phonograph, the diaphragm for the reproducer being indicated at 7. Numeral 8 indicates the stylus-bar having a stylus 9 adapted to engage the disk-record 10.

A support is provided for the stylus-bar consisting, in part, of an apertured bearingdisk 11 which is rigidly connected with the lower part of the reproducer by means of the pair of arms 12, a second apertured bearing-disk 18 being disposed below and having a collar 1 1- disposed in the aperture of the disk 11, a third apertured bearingdisk 15 being disposed above the disk 13 and having a threaded connection with the collar 14, whereby the lower disk may have a limited swinging movement horizontally.

The lower disk 13 is provided with a pair of hangers 16, these being disposed upon opposed sides of the stylus-bar. Numerals Specification of Letters Patent.

semi 1%. 323,169.

17 indicate a pair of pivot-pins engaging the opposed sides of the tylus-bar, said pins being threaded in the hangers 16, whereby said bar may have swinging movements for the stylus toward and from the disk-record. Numerals 18 indicate roller balls disposed between the bearing-disks 11 and 13, and numerals 19 indicate rollerballs disposed between the disks l3 and 15, said balls operating to facilitate the movements of the lower disk together with the hangers and stylus-bar.

At 20 is indicated a cord having its upper end mounted in and compressed by a split, tubular pin 21 which is secured to the diaphragm by means of nuts 22, its lower end being connected with the stylus-bar means of the hook 26 and the eye connected therewith, best shown in Fig. d, said cord being drawn to a taut condition when the parts are assembled.

Gn account of the construction thus described, the stylus-bar may have the required vertical and horizontal swinging movements to permit the stylus to remain in the spiral groove of the disk record without excessive jolts or jars which conduces to the production of a clear tone, which is one of the objects'of the invention.

in armature is secured to that end of the bar 8, opposite to the stylus, said armature consisting of a spherical segment 23, and at is indicated a suitably supported electromagnet which is disposed in operative proximity to the armature, the core 25 of the electromagnet having a concaved surface corresponding to the convened surface of the armature.

The stylus-bar is of such proportion that it is suitably balanced at its pivotal mounting 17, and in the present instance a counterbalance 27 is shown for this purpose.

It will be appreciated that, since the cord 20 is disposed at the longitudinal axes of the disks 11, 13 and 15, and has its lower end mounted in line with the pivots 17 which provide the pivotal mounting of the stylus-bar, the tension of said cord will remain practically uniform during the swing ing movements of the stylus-bar, this being an important feature; also, since the parts of the outer surface of the armature 23 which are closely adjacent to the concaved surface of the core 25 are equidistant from said core, the movement of the armature toward the electromagnet will be gradual and uniform, regardless of the direction Patented Nov. 2, 1920. y

of the swinging movement of the stylus-bar. During operation, the stylus-bar has an undulatory movement which is occasioned by the revoluble movement of the disk-record,

- and therefore the stylus-bar will swing horizontally as well as vertically, and the curvatures provided by the spherical segment 23 and the surface of the core 25 which conforms thereto are considered to be of great advantage.

The distinguishing feature shown in the present invention relating to the electromagnet and armature is the fact that the surfaces of the elements which lie adjacentto each other have a curvature whose common center is the pivotal mounting of the stylus-bar. I

It will be understood that the stylus 9 will be pressed against the disk record 10 by operation of the electromagnet and armature 23, this being of advantage to'prevent shifting of the stylus from one part to an adjacent part of the spiral groove especially if the groove is shallow or is disposed inclinedly.

lVhile l have described construction in detail I do not wish to be understood as limiting myself to exactness in this respect, and changesin form, size, proportion and minor details may be made as found to be of advantage, said changes depending upon the scope of the invention as claimed.

1 claim:

1. In combination with the diaphragm of the reproducer, a; pivotally mounted stylusbar provided with a curved armature, a'cord connecting the diaphragm with the stylusbar approximately at the pivotal mounting thereof, and an electromagnet provided with a core having a curvature for its terminal corresponding approximately to the curve.-

'ture of and disposed in operative proximity to-said armature. V r r 2. In combination with the diaphragm and pivotally mounted stylus-bar or the re producer, said stylus-bar bein provided with an armature having the form of a spherical segment, a cord connecting the diaphragm with the stylus-bar approximately at the pivotal mounting thereof, and an electromagnet provided with a core having a curved surface for its terminal corresponding approximately to the curvature of and disposed in operative proximity to said armature.

3. In combination with the diaphragm and axially mounted stylus-bar of the reproducer, said stylus-bar being provided at one of its ends with an armature having a curved outer surface and disposed with all parts of said curved surface equidistant from said axial mounting, a cord connecting the diaphragm with the stylusbar approx-L mately at the axial mounting thereof, and an electromagnet having a core provided near/sea second apertured bearing-disk having hangers disposed below and carried by the irst named bearing-disk, balls between sald bearing-dislrs, a stylus-bar provided with an armature, said bar being disposed between and having pivotal connection with said hangers, a cord connected with the diaphragm and traversing the apertures of the bearingdisks for amounting upon the. stylus-bar approximately at the pivotal connection of said bar with said hangers, and anelectromagnet having a core disposed adjacent to said armature.

5. The combination with the reproducer of a phonograph and the diaphragm within said reproducer, an apertured bearing-disk car ied by the reproducer and provided with hangers, a second bearing-disk below and having a collar disposed in the aperture of the first named bearing-disk and provided with hangers, a third apertured bearing-disk above the first named bearingdisk and having a threaded connection with said collar, halls between said bearing-disks, a stylushar between and having a pivotal connection with the second named hangers, said bar being provided with a metallic, spherical seg merit, a cord connected with the diaphragm and traversing the collar of the second bearing-disk and connected with the stylus-bar approximately at its pivotal connection with said hangers, and an electromagnet provided with a core having a curved surface for its terminal corresponding approximately to the curvature of and disposed adjacent to the metallic, spherical segment of the stylusbar.

6. In combination with the diaphragm and axially mounted stylus-bar of the reproducer, hangers ielow the diaphragm, a stylus-bar provided with an armature and pivotally connected with the hangers, devices between. the stylus-ba-r and diaphragm arranged to permit horizontal and vertical movements of said stylus bar, a cord connecting the diaphragm with the stylus-bar approximately at the pivotal connection of said bar with the hangers, and an clectro- 

